Copyright © University of Cambridge. All rights reserved.

'First Forward Into Logo 9: Stars' printed from http://nrich.maths.org/

Show menu

First Forward Into Logo
Previous: FF8


In FF7 you looked at the following procedures and were invited to alter them at your leisure:

TO POLY :N
REPEAT :N [FD 45 RT 360/:N]
END

TO POLY :N :M
REPEAT :N [FD :M RT 360/:N]
END

Now...two activities:

Activity one:
Consider REPEAT 5 [ FD 100 RT 144] .........what do you think this means? Try to imagine what is happening before entering the procedure into a machine. Imagine being the 'turtle' that creates the graphic....how many times does it turn? Through how many degrees has it turned when it has finished the procedure?

Activity two:
Consider the procedure below. What do you think is happening? Talk through with your friends what you think the procedure is all about. Only then enter it into a machine and experiment with it.
TO GAZE :M :N
REPEAT :N [ FD :M LT 720/:N]
END

Try GAZE 100 5;
GAZE 120 7;
GAZE 200 9;
GAZE 50 8 (Beware maybe not what you think!)
Okay then what about GAZE 150 12?
GAZE 250 16?



stars Alternatively, you might like to write a procedure for any of these shapes. Walk them first - either in your mind or in the playground.

You might also be interested in how the shapes were flled with colour.

This needs two new commands:

SETFLOODCOLOUR [:red :green :blue].
This works in a similar way to SETPC described in FF3.

FILL
This is the command that you use to fill your shape with the "Flood Colour" .
One word of warning - you have to be inside the shape to fill it!

 

Next: FF10